The Four Kings of Heaven (Shitennou) are the 4 generals of the Dark Kingdom who serve under Queen Beryl.
In their past lives the Four Kings of Heaven were originally knights in the service of the Earth Prince Endymion and fell in love with the Sailor Guardians assigned to protect Princess Serenity. However, through cruel fate, the quartet were placed under Beryl's spell and became her slaves when she returned and established the Dark Kingdom. This made them the enemies of the Sailor Guardians as a result. After their deaths, the Four Kings returned to their reincarnated master's side as magic stones to continue aiding him as his advisors.
- Each of the Four Kings have names which are derived from the name of a gemstone.